package com.TT.ticket.pc;


/**
 * 线程之间的通信问题：生产者和消费者问题!  等待唤醒，通知唤醒
 * 线程交替执行  A  B 操作同一个变量   num=0
 * A  num+1
 * B  num-1
 */
public class A {
    public static void main(String[] args) {
        Data data = new Data();


        new Thread(()->{
            for (int i=0;i<10;i++){
                try {
                    data.increatment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"A").start();

        new Thread(()->{
            for (int i=0;i<10;i++){
                try {
                    data.decreatment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"B").start();
    }
}


/**
 * 判断等待，业务，通知
 */

/**
 * 如果是多个线程，使用if判断会产生虚假唤醒问题，所以改为while即可解决
 */
class Data {  //数字 资源类

    private int number = 0;


    //+1
    public synchronized void increatment() throws InterruptedException {
        while (number != 0) {
            //等待
            this.wait();
        }
        number++;
        System.out.println(Thread.currentThread().getName() + "=>" + number);
        //通知其他线程，我+1完毕了
        this.notifyAll();
    }

    //-1
    public synchronized void decreatment() throws InterruptedException {
        while (number == 0) {
            //等待
            this.wait();
        }
        number--;
        System.out.println(Thread.currentThread().getName() + "=>" + number);
        //通知其他线程，我-1完毕了
        this.notifyAll();
    }

}
